Grade 7 Probability Practice Test

Correct answer: A

The correct answer is $10$.

1. Describe the sample space: Count the equally likely outcomes or identify the favorable outcomes for the event.
2. Calculate the probability: The probability of a six is $\frac{1}{6}$. Expected sixes: $60\cdot\frac{1}{6}=10$.
3. Check the result: Confirm that the probability is between 0 and 1 and that the fraction or decimal is simplified.

Correct answer: B

The correct answer is $20$.

1. Describe the sample space: Count the equally likely outcomes or identify the favorable outcomes for the event.
2. Calculate the probability: The probability of heads is $\frac{1}{2}$. Expected heads: $40\cdot\frac{1}{2}=20$.
3. Check the result: Confirm that the probability is between 0 and 1 and that the fraction or decimal is simplified.

Correct answer: C

The correct answer is $20$.

1. Describe the sample space: Count the equally likely outcomes or identify the favorable outcomes for the event.
2. Calculate the probability: Expected wins are $80\cdot\frac{1}{4}=20$.
3. Check the result: Confirm that the probability is between 0 and 1 and that the fraction or decimal is simplified.

Correct answer: D

The correct answer is $20$.

1. Describe the sample space: Count the equally likely outcomes or identify the favorable outcomes for the event.
2. Calculate the probability: Expected rolls are $120\cdot\frac{1}{6}=20$.
3. Check the result: Confirm that the probability is between 0 and 1 and that the fraction or decimal is simplified.

Correct answer: A

The correct answer is $\frac{1}{10}$.

1. Describe the sample space: Count the equally likely outcomes or identify the favorable outcomes for the event.
2. Calculate the probability: Assuming distinct tickets, the probability is $\frac{5}{50}=\frac{1}{10}$.
3. Check the result: Confirm that the probability is between 0 and 1 and that the fraction or decimal is simplified.

Correct answer: B

The correct answer is $4$.

1. Describe the sample space: Count the equally likely outcomes or identify the favorable outcomes for the event.
2. Calculate the probability: The outcomes are HH, HT, TH, and TT, so there are 4 outcomes.
3. Check the result: Confirm that the probability is between 0 and 1 and that the fraction or decimal is simplified.

Correct answer: C

The correct answer is $6$.

1. Describe the sample space: Count the equally likely outcomes or identify the favorable outcomes for the event.
2. Calculate the probability: Use the multiplication principle: $3\cdot2=6$ outfits.
3. Check the result: Confirm that the probability is between 0 and 1 and that the fraction or decimal is simplified.

Correct answer: D

The correct answer is $\frac{1}{2}$.

1. Describe the sample space: Count the equally likely outcomes or identify the favorable outcomes for the event.
2. Calculate the probability: There are 5 even digits out of 10: $\frac{5}{10}=\frac{1}{2}$.
3. Check the result: Confirm that the probability is between 0 and 1 and that the fraction or decimal is simplified.

Correct answer: A

The correct answer is $\frac{4}{25}$.

1. Describe the sample space: Count the equally likely outcomes or identify the favorable outcomes for the event.
2. Calculate the probability: With replacement, multiply $\frac{4}{10}\cdot\frac{4}{10}=\frac{16}{100}=\frac{4}{25}$.
3. Check the result: Confirm that the probability is between 0 and 1 and that the fraction or decimal is simplified.

Correct answer: B

The correct answer is $\frac{5}{14}$.

1. Describe the sample space: Count the equally likely outcomes or identify the favorable outcomes for the event.
2. Calculate the probability: Multiply without replacement: $\frac{5}{8}\cdot\frac{4}{7}=\frac{20}{56}=\frac{5}{14}$.
3. Check the result: Confirm that the probability is between 0 and 1 and that the fraction or decimal is simplified.